xref: /linux/drivers/xen/biomerge.c (revision f3539c12d8196ce0a1993364d30b3a18908470d1)
1 #include <linux/bio.h>
2 #include <linux/io.h>
3 #include <linux/export.h>
4 #include <xen/page.h>
5 
6 bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
7 			       const struct bio_vec *vec2)
8 {
9 #if XEN_PAGE_SIZE == PAGE_SIZE
10 	unsigned long bfn1 = pfn_to_bfn(page_to_pfn(vec1->bv_page));
11 	unsigned long bfn2 = pfn_to_bfn(page_to_pfn(vec2->bv_page));
12 
13 	return __BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&
14 		((bfn1 == bfn2) || ((bfn1+1) == bfn2));
15 #else
16 	/*
17 	 * XXX: Add support for merging bio_vec when using different page
18 	 * size in Xen and Linux.
19 	 */
20 	return 0;
21 #endif
22 }
23 EXPORT_SYMBOL(xen_biovec_phys_mergeable);
24